This invention relates to devices for diverting the path of flowing fluids in at least two directions, and more particularly to a system for recirculating a selected amount of wastewaterin a wastewater treatment system.
In the treatment of wastewater, such as sewage and the like, it is common to provide a septic tank with an inlet pipe from the source and an outlet pipe for discharge from the tank. Solids in the wastewater settle out to the bottom of the tank while the clarified effluent flows from the tank through the outlet pipe. Effluent leaving the effluent tank may undergo further filtration to remove remaining undissolved particulate materials by passing the effluent through screen filters or similar devices. The effluent may be transported to a second tank for further settling and treatment to remove harmful constituents. Finally, the effluent may be piped into a lateral field where it is passed into a soil bed.
Optionally, wastewater can be further treated before discharge into the environment by utilizing a recirculating system. After leaving the septic tank in a recirculating system, the effluent is passed through a treatment media, which cleans the effluent by filtration and/or bioremediation, and then back to the septic tank, to a separate recirculation tank or back through the filtering system. The filtering system may be a filter bed comprised of stratified, layers of sand, gravel or possibly organic matter, wherein the effluent is loaded into the top of the system and trickles through the system to the bottom for collection. The filtering system may include polyurethane or other types of open cell foam having a large surface area through which the effluent trickles and is treated by microorganisms in an aerobic environment.
At some point, the recirculating effluent passes out of the recirculating system and to a receiving body, for example a drain field. A mechanism diverts the filtered effluent to the receiving body. One mechanism utilized is to simply divert a portion of the total effluent returned from filtration through the filtering system. However, this potentially results in a percentage of the wastewater passing through the filtration system only once before discharge. Further, if a sufficient quantity of wastewater is not constantly added to the system to offset the constant flow out of the system, the water level may drop enough that the pumps are damaged by running dry and/or the filtering system dries out, killing essential organisms necessary for treatment of the effluent. Also, if the volume increases faster than the amount of effluent removed from the system, it can overflow.
Alternatively, a means of detecting either effluent flow or effluent level in the septic tank or recirculation tank is used to direct the effluent either out to a drain field or back into the treatment media. Thus, if effluent volume within the system is detected as reaching a critical maximum or minimum, a device seals one of the passages, either to the drain field or back into the system, and diverts the flow where it is needed. The sealing device may be a caged ball float that acts to seal a pipe when the water level within a tank rises enough to force the float over the pipe opening. This system has the disadvantage of diverting all or none of the effluent volume. Thus, it is possible that improperly filtered effluent can be discharged from the system if the level rises too high and all the effluent is diverted directly to the drain field. Further, the ball float makes an inferior valve in that it may not seal properly and is difficult to adjust so that it seals at the proper fluid level.
It would be advantageous to have a recirculation device for use in septic systems employing treatment media that sense the level of effluent and divert only a portion of the effluent when required. Such a system would have the advantage of ensuring adequate filtration of all effluent before discharge from the system. Such a system would be most beneficial for treatment systems where the flow volume varied greatly over time.
It is accordingly a primary object of the present invention to provide a recirculation device for use in recirculating septic systems that redirects a portion of flowing wastewater out of the system to a receiving body.
Further, it is an object of the present invention to provide such a recirculation device that is capable of sensing the volume of fluid within the system and when the volume reaches a critically low level, retain all of the fluid within the system so that it is continually recirculated until the fluid volume again rises above the critical level.
It is an even further object of the present invention to provide such a device wherein the percentage of fluid that is diverted to the receiving body can be determined by the user and also altered with relative ease by the user post-installation.
More particularly, the recirculating wastewater treatment system in which the present invention is used comprises a septic tank having an inlet pipe that discharges untreated wastewater into the septic tank from the waste source. The septic tank also has an outlet pipe that may or may not have a filter attached. While in the septic tank, the solids settle to the bottom of the tank and degrade while the clarified effluent flows out of the septic tank through the outlet pipe. The effluent may enter a second tank either separate from the septic tank or merely divided from the septic tank by a wall. The effluent undergoes further settling and separation of undissolved solids from the liquids while in the second tank. The effluent is pumped out of the second tank, or directly from the septic tank into a treatment media. This system further filters and purifies the effluent. The system may percolate the effluent through multiple porous strata, such as gravel, sand and/or peat that serves as a filtering media. Alternatively, and more preferably, the system may percolate water through an open cell foam having a large surface area colonized with bioactive microorganisms that serves as a filtering media and facilitates the degradation of organic contaminants within the effluent.
A percentage of the collected and cleaned effluent is recycled and returned via the recirculation device of the present invention to the tank(s) and passed again through the treatment media, while the remainder of the treated effluent is discharged to a receiving body, for example a drain field. Alternatively, if the recirculation device senses a critically low total fluid volume within the system, it will recirculate all of the cleaned effluent back through the system until the total volume increases above the critical level.
Specifically, the present invention is directed to a fluid diverting recirculation device located within a tank of a recirculating septic system. The tank may be a septic tank, a secondary settling tank, or a tank specifically for housing the recirculation device. The recirculation device is comprised of a splitter pipe in flow communication with the treatment media. The splitter pipe has openings therein that permit a percentage of the water returning from the treatment media to flow into the tank. The openings have flow leveling devices covering them that allow the user to direct the flow of water evenly out of each opening even if the splitter pipe is not level. The flow leveling devices can also be adjusted so that more or less effluent exits one or more openings than one or more other openings. This permits fine adjustment of the percentage of effluent that recirculates back into the system. The splitter pipe is further fluidly connected with a valve device, comprised of a valve conduit or housing and a valve mechanism, which in turn is fluidly connected with the receiving body. The valve conduit houses the valve mechanism, which is comprised of a valve, a valve guide rod connected to the valve and extending into the tank a predetermined distance, and a float attached to the rod and floating in the effluent. The valve moves vertically within the valve conduit in response to the effluent level within the tank raising or lowering the float. If the effluent level drops below a critical level, the valve will drop far enough that the flow communication with the drain field is blocked. This forces all of the effluent returning to the splitter pipe to exit through the openings in the splitter pipe and reenter the treatment media through the tank. When the effluent level in the tank rises above the critical level, the valve will rise and permit a percentage of the filtered effluent to exit to the drain field once again.
A better understanding of the invention will be had upon reference to the following description in conjunction with the appended claims and accompanying drawings in which like numerals refer to like parts throughout the several views.